public async Task DeleteVendor_ReturnsTrue()
{
// arrange
var vendor = new Vendor {
id = 123
};
_vendorsQueryMock.Setup(x => x.Delete(vendor.id.Value))
.Returns(Task.Factory.StartNew(() => true));
// act
var task = await _sut.Delete(vendor.id.Value);
// assert
Assert.IsType <OkObjectResult>(task);
var result = task as OkObjectResult;
var usersResult = result.Value as bool?;
Assert.True(usersResult.Value);
}